An EMS ambulance pulls out of of Terminal B at Bush Intercontinental Airport on Thursday, May 2, 2013 in Houston. / Karen Warren, AP

by Gregory Korte, USA TODAY

by Gregory Korte, USA TODAY

HOUSTON -- Shots fired near a ticket counter left one man dead and created a scare this afternoon at Houston's busy George Bush Intercontinental Airport.

The episode has delayed some flights to and from the airport, mostly on United -- which has waived change fees for customers flying through Houston today.

The incident began when an as-yet unidentified man entered the airport's Terminal B and fired a gun toward the ceiling at around 1:35 p.m. CT, Houston Police Department spokesman Kese Smith told reporters at the airport.

Smith says a Department of Homeland Security (DHS) official stationed at the airport heard the commotion and moved to the scene, where he gave the man a verbal warning to drop his weapon. When the man did not comply, the DHS official fired at the suspect.

At about the same time, according to Smith, the suspect appeared to turn his own gun on himself. Kese says shots were fired from both weapons, but it was not clear whose shots killed the suspect, who was pronounced dead at the airport. That will be determined in an autopsy, according to Kese.

Passenger Dale Howard of Tomball, Texas, tells The Associated Press he was at the baggage handling area of the airport waiting for his sister to arrive on an incoming flight when he heard two shots fired from the floor above. A few seconds later, he said he heard three more shots.

"People were screaming. I knew exactly what it was - gunfire," Howard says to AP.

Given the shooting's location, Smith of the Houston police said it's fortunate no one else was hurt.

"The good news is that there were no passengers injured," Smith says. "This something that's very important to keep in mind."

The airport adds via Twitter that Terminal B operations are "being redirected to other terminals. (Passengers) are being allowed to move to other terminals. It's a slow process due to heavy (passenger) traffic and limited train access."

"It's still an active scene. We're asking people to be patient.," Ward says.

The airport advised passengers were advised to check with their airlines on the status of their flights.

By 2:10 p.m. CT, the Federal Aviation Administration had issued a "ground stop" for flights bound for Houston Bush Intercontinental, citing "security" as the reason. The ground stop was still in place as of 4:30 p.m. CT.

United Airlines announced on Thursday afternoon that it would waive change fees for passengers flying through Houston today in an apparent effort to get ahead of flight disruptions caused by the incident. United is by far the biggest carrier at Houston Intercontinental. Terminal B houses regional flights operated by United's United Express partner airlines.

The incident comes as many passengers are arriving for the National Rifle Association's annual convention, which is being held in Houston from Friday through Sunday.